JPH09277724A - Ohp sheet with formed image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a projection image projected from an OHP sheet, especially its highlighted part clearly visible as an image with a sharp contrast. SOLUTION: This OHP sheet with a formed image comprises at least a transparent receptive layer formed on a transparent base material with an image formed in sublimable dye in the transparent receptive layer. Of the formed image, a magenta image has a turbidity which is 20-30% when the density of a magenta component is 0.5 or less. In addition, a cyan image has the turbidity which is 30-40% when the density of a cyan component is 0.5 or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an OHP (overhead projector) sheet, and more particularly to an OHP sheet in which a formed image is clear and has contrast.

[0002]

2. Description of the Related Art Image formation by a thermal sublimation transfer recording system is carried out, for example, on a thermal transfer sheet having a dye layer composed of a sublimable dye and a binder resin formed on one side of a base film, and on a white foam film base. A thermal transfer image-receiving sheet having a receptive layer is used, and these are superposed and heated by a thermal head from the back surface of the thermal transfer sheet to form an image with a sublimable dye on the receptive layer of the thermal transfer image-receiving sheet.

[0003]

However, in the case of forming an image on an OHP sheet, if an image is formed by using a normal thermal transfer sheet, the image becomes whitish and thin as a whole. This is because the OHP sheet uses a PET (polyethylene terephthalate) film as a base material, and the cushioning property of the base material is low, resulting in poor adhesion to the thermal transfer sheet at the time of printing, resulting in insufficient dye transfer. It seems that the density of the image becomes low. Especially,
This phenomenon was remarkable in the highlight area where the density was low.
For this reason, the OHP sheet on which the image is formed is
When projected with HP), a clear image could not be obtained.

[0004]

Therefore, the OHP sheet on which the image of the present invention is formed has a density area which becomes a highlight portion of a magenta image portion or a cyan image portion of the formed image. By not having a pure magenta color or a cyan color and having other color components on purpose, by setting the turbidity, which can be said to be the content of the other color components, to a specific range, the whiteness is eliminated, A sharp image was obtained. Specifically, the magenta image portion has a magenta turbidity of 2 when the density of the magenta component is 0.5 or less.
0 to 35%. In the cyan image portion, when the density of the cyan component is 0.5 or less, the turbidity of cyan is 30 to 40.
%.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the OHP sheet on which the image of the present invention is formed will be described below. Turbidity is a numerical value that represents the degree of turbidity of colors. High turbidity results in a dark color that is turbid in appearance, and low turbidity results in a transparent color with high transparency. The "turbidity" is called "turbidity". When the turbidity of the image formed on the OHP sheet becomes a specific value or more, for example, even if the density is low, the image becomes clear and has a high contrast. Since the OHP sheet has low cushioning properties, it is difficult to increase the image density. However, by forming an image with high turbidity without increasing the image density, it is possible to obtain a clear contrast when projected on the OHP sheet. It is possible to form an image having In the present invention, the OHP is defined by defining the turbidity of magenta and cyan images, which are colors that greatly affect the contrast of the image.
We paid attention to the fact that a clear and high-contrast image can be formed on the sheet.

The turbidity is measured by the following method. First, a magenta image is formed on an OHP sheet using a thermal transfer sheet. Next, the density of the magenta component of the formed magenta image (denoted as Mm. The same applies hereinafter), the density of the yellow component (My), and the density of the cyan component (Mc) are measured.
The turbidity (D) is calculated by the following formula using the highest numerical value (H) and the lowest numerical value (L) of the concentrations of these three components. D [%] = (L / H) × 100 For example, Mm is 0.5, My is 0.06, and Mc is 0.0.
In the case of 5, the highest numerical value (H) is 0.5 of Mm and the lowest numerical value (L) is 0.05 of Mc. Therefore, the turbidity Dm of the magenta image is Dm = 0.05 / 0.5 × 100 = 10 [%]. Similarly, a cyan image is formed, the cyan component density (Cc), the yellow component density (Cy), and the magenta component density (Cm) are measured, and the turbidity (Dc) of the cyan image is calculated.

In the present invention, the turbidity of the magenta image needs to be in the range of 20% to 35% when the density (Mm) of the magenta component of the magenta image formed on the OHP sheet is 0.5 or less. is there. Alternatively, when the density (Cc) of the cyan component of the cyan image formed on the OHP sheet is 0.5 or less, the turbidity of the cyan image needs to be in the range of 30% to 40%. By forming an image in the above range, a clear and high-contrast image can be formed even when an OHP sheet is used as a recording medium. When the turbidity is less than the above range, the image is whitish and unclear as a whole, and when it is more than the above range, the image is strongly black and dark, which is not preferable. As for the turbidity of magenta and cyan, it is sufficient that either one of the colors has a turbidity within the above range, but it is preferable that both of the two colors have a turbidity within the above range. The turbidity of the yellow image is 10%
It is preferably in the range of ˜30%.

The thermal transfer sheet and OHP sheet that can be used to obtain the image-formed OHP sheet of the present invention will be described below.

Regarding the thermal transfer sheet: The thermal transfer sheet may have a conventionally known structure in which at least a dye layer is provided on a base film, and the sublimable dye constituting the dye layer may have the turbidity described below. Use a dye that considers the degree.

Dye layer In the present invention, by defining the range of turbidity of the image formed on the OHP sheet, a clear and contrasty image can be obtained. The selection of the sublimable dye used in the dye layer of the thermal transfer sheet is important. As the sublimable dye, one or more dyes having high turbidity when printed are used, and the dye layer is formed so that the turbidity is within the above range. Examples of such sublimable dyes include the following dyes. First, examples of magenta dyes include anthraquinone dyes. Specific examples of the anthraquinone dye include Macrolex R.I. VR-SS (made by Bayer) is mentioned. Other than the anthraquinone system, Biscript S. RT (manufactured by Bayer), Oil Red # 5304SS (manufactured by Arimoto Chemical Co., Ltd.) and the like can also be used. Next, as a cyan dye, anthraquinone dye, specifically DH-C2
(Nippon Kayaku Co., Ltd.) can be used. Further, Fluoron Brilliant Blue S-Rpig (manufactured by Sand Co.) is also a dye for increasing the turbidity. Further, as the yellow dye, Fluoron Brilliant Yellow S-6GL pig (manufactured by Sand Co.) and Microlex Yellow 6G (manufactured by Bayer Co.)
And other dyes.

The dye having a high turbidity when an image is formed is not limited to the above dyes. Further, as the dye used in the dye layer, not only the above-mentioned dye having a high image turbidity but also a dye having a low turbidity may be used in combination. As a means for increasing the turbidity, a yellow dye is added to the magenta or cyan dye layer in an amount of 1 to 5% by weight based on the solid content of the main color, in addition to the above-described dye for increasing the turbidity. You may adjust the turbidity by

As the binder resin constituting the dye layer, a conventionally known binder resin such as ethyl cellulose,
Hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, methylcellose, cellulose nitrate, cellulose acetate, cellulose-based resins such as acetic acid and cellulose butyrate, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal-based resins such as polyvinyl acetoacetal,
Examples thereof include vinyl resins such as polyvinylpyrrolidone, polyesters and polyamides, and there is no particular limitation.

[0013] As the base film of the substrate film thermal transfer sheet, for example, it can be used a plastic film, paper, cellophane or the like, not particularly limited. As a plastic film,
Polyester films such as polyethylene terephthalate film and polyethylene naphthalate film, polypropylene film, polyamide film, polystyrene film, polyvinylidene chloride film, polyvinyl chloride film, EVOH film, polycarbonate film, fluororesin film, polymethylmethacrylate film, polybutene-1. Examples include films, polyimide films, polyetheretherketone films, polysulfone films, polyethersulfone films, polyetherimide films, polyphenylene sulfide films, polymethylpentene films, and the like. Among them, polyethylene terephthalate film, polyethylene naphthalate film, and polyether ether ketone film having high heat resistance are preferable. The surface of these plastic films may be subjected to surface treatment such as easy adhesion treatment, antistatic treatment and corona treatment.

Heat-Resistant Sliding Layer The thermal transfer sheet for obtaining the image-formed OHP sheet of the present invention is not particularly limited as long as it has at least the above-mentioned dye layer in the base film.
The OHP sheet requires an image density higher than that of the image receiving paper, which is a paper base material, in order to see the transmitted image, and the base material of the OHP sheet does not have the heat insulating property like the paper base material, and the thermal transfer sheet is heated by the thermal head. Is preferably strong. In this respect, a structure in which a heat resistant slipping layer is provided on the back surface side opposite to the dye layer in order to supplement the heat resistance of the base film is a preferred structure of the thermal transfer sheet.

The heat resistant slipping layer usually comprises a binder resin, a lubricant and a filler. As the binder resin, one that has heat resistance and does not exhibit heat fusion property when heated is used, and, for example, urethane resin, melamine resin, epoxy resin, silicone resin and the like can be used. Above all, a resin as a reaction product of an isocyanate and an active hydrogen-containing thermoplastic resin having active hydrogen is preferable.

As the active hydrogen-containing thermoplastic resin, a conventionally known thermoplastic resin having active hydrogen can be used.
Examples thereof include thermoplastic resins such as polyester resins, polyurethane resins, polyvinyl acetate resins, polyacrylamide resins, polyvinyl butyral resins, polyvinyl acetal resins such as polyvinyl acetoacetal resins. Among these, a particularly preferable resin is a thermoplastic resin having active hydrogen as a hydroxyl group, and among them, a polyvinyl acetal resin such as a polyvinyl butyral resin or a polyvinyl acetoacetal resin is particularly preferable. As the isocyanate, various conventionally known polyisocyanates can be used, and among them, the polyisocyanate of an adduct of aromatic polyisocyanate is preferable. Those isocyanate compounds are compounds having two or more isocyanate groups, and any of the isocyanate compounds used in the conventional technology relating to polyurethane resins can be used. For example, TD
I (tolylene diisocyanate), MDI (diphenylmethane diisocyanate), NDI (1,5-naphthalene diisocyanate), TODI (trizine diisocyanate), HDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), p-
Phenylene diisocyanate, XDI (xylylene diisocyanate), hydrogenated HDI, hydrogenated MDI, LDI (lysine diisocyanate), TMXDI (tetramethyl xylene diisocyanate), lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8 -Diisocyanate-4-isocyanate methyl octane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, TM
Examples thereof include DI (trimethylhexamethylene diisocyanate), but other compounds having an isocyanate group can be used and are not limited to these. In fact, Takenate (manufactured by Takeda Pharmaceutical Co., Ltd.), Barnock (manufactured by Dainippon Ink and Chemicals, Inc.), Coronate (Japan Polyurethane Industry Co., Ltd.)
, Duranate (manufactured by Asahi Kasei Kogyo Co., Ltd.), and Dismodule (manufactured by Sumitomo Bayer Urethane Co., Ltd.).

The amount of isocyanate added is 5 to 280 with respect to 100 parts by weight of the binder resin constituting the heat resistant slipping layer.
A range of parts by weight is appropriate. In the NCO / OH ratio of 0.
A range of about 6 to 2.0 is preferable. If the amount of isocyanate used is too small, the crosslinking density is low and the heat resistance is insufficient,
Further, when the curing time becomes long, on the other hand, when the amount is too large, the shrinkage of the coating film formed cannot be controlled, and when unreacted NCO groups remain in the heat resistant slipping layer, they may react with moisture in the air or the dye layer. It may act negatively, such as reacting with the binder resin or dye.

Further, in place of or in combination with the above-mentioned isocyanate, a monomer or oligomer having an unsaturated bond is used in combination for the purpose of improving heat resistance, coating property and adhesion to the base film in the heat resistant slipping layer. can do. When a monomer or oligomer having an unsaturated bond is used as a cross-linking agent, the curing method may be curing by electron beam or ultraviolet irradiation, but when a large amount of filler is added, curing by electron beam irradiation Is desirable. Examples of the monomer or oligomer having an unsaturated bond include tetraethylene glycol di (meth) acrylate [(meth) acrylate means both acrylate and methacrylate. The same applies hereinafter. ], Difunctional monomers such as divinylbenzene and diallyl phthalate, trifunctional monomers such as triallyl isocyanurate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, trimethoxyethoxyvinylsilane and the like, and pentafunctional The above monomers and oligomers and macromers composed of these monomers can be mentioned.

As the lubricant to be added to the heat resistant slipping layer for improving slipperiness, various conventionally known lubricants can be used, and among them, phosphate ester type surfactants are preferable. Examples of the phosphoric acid ester-based surfactant include (1) long-chain alkyl phosphoric acid ester, for example, saturated or unsaturated higher alcohol having 6 to 20 carbon atoms, preferably 12 to 18 carbon atoms, such as cetyl alcohol. , Phosphate monoester or diester of alcohols such as stearyl alcohol and oleyl alcohol. (2) Phosphoric acid monoester salts or diester salts such as polyoxyalkylene alkyl ethers and polyoxyalkylene alkyl allyl ethers. (3) Alkylene oxide adducts of the saturated or unsaturated higher alcohols (usually 1 to 1 moles added)
8), or phosphoric acid monoester salts or diester salts of alkylphenols or alkylnaphthols (nonylphenol, dodecylphenol, diphenylphenol, etc.) having at least one, preferably 1-2, alkyl groups having 8 to 12 carbon atoms, etc. Anionic phosphate ester-based surfactants are listed.

Although only the above-mentioned phosphoric acid ester-based surfactant may be used, since the phosphoric acid ester-based surface lubricant has 1 to 2 equivalents of acid groups, the thermal head is formed by this acid group. The problem of corroding arises. Further, when the amount of heat from the thermal head becomes large, the phosphate ester is decomposed, the pH of the heat resistant slipping layer is further lowered, and the corrosion and wear of the thermal head becomes severe. These drawbacks can be prevented by using an alkaline substance together with a phosphate ester-based interfacial lubricant. That is, even if the phosphate ester type surfactant is decomposed by the heat from the thermal head to generate an acid group, it is neutralized by the coexisting alkaline substance, so that the corrosion of the thermal head due to the generation of the acid group can be prevented. The amount of phosphate ester surfactant added is
The range of 50 to 120 parts by weight is preferable with respect to 100 parts by weight of the binder resin. If it is less than 50 parts by weight, sufficient slipperiness cannot be obtained, and conversely, if it exceeds 120 parts by weight, dye stainability increases.

Examples of the alkaline substance include oxides or hydroxides of alkali metals or alkaline earth metals, or organic amines. Preferred as the oxide or hydroxide of an alkali metal or alkaline earth metal are, for example, magnesium hydroxide, magnesium oxide, hydrotalcite, aluminum hydroxide,
Aluminum silicate, magnesium silicate, magnesium carbonate, alumina hydroxide, magnesium aluminum glycinate and the like can be mentioned, and as particularly preferable ones,
It is magnesium hydroxide. Preferred organic amines are, for example, mono-, di- or tripropylamine, mono-, di- or tributylamine, mono-, di- or tripentylamine, trihexylamine, trioctylamine,
Monodecylamine, mono or didodecylamine, monotridecylamine, monotetradecylamine, monopentadecylamine, monohexadecylamine, monoheptadecylamine, monooctadecylamine, monoeicosylamine, monodocosylamine, mono , Di- or triethanolamine, mono- or dipropanolamine, monoisopropanolamine, N-methyl-nonylamine, N-
Methyl-decylamine, N-ethyl-palmitylamine and the like can be mentioned. Particularly preferred organic amines are non-volatile at room temperature and have a boiling point of 200 ° C or higher. These organic amines are stably present in the heat resistant slipping layer, and when heat is applied from the thermal head to the heat resistant slipping layer, they become fluid and bleed out on the surface, and a phosphate ester-based surfactant or The acid group generated in the decomposed product is easily neutralized to prevent corrosion of the thermal head, and at the same time, it exhibits excellent slipperiness together with the phosphate ester surfactant. As for the alkaline substance as described above, it is desirable to use the alkaline substance in the range of 0.1 to 10 mol per 1 mol of the phosphate ester surfactant. If the amount of the alkaline substance is too small, sufficient effect cannot be obtained because the neutralization is insufficient. On the other hand, if the amount is too large, no particular improvement in the effect is observed.

Further, in order to stabilize the processability of the thermal transfer sheet, stabilize the printing running property, and impart the cleaning property of the thermal head,
It is desirable to use inorganic or organic fillers. When the filler is selected, it is required that the filler has a particle size and a shape sufficient to form unevenness on the surface of the heat resistant slipping layer, and that the thermal head is less worn. Examples of usable fillers include talc, kaolin, clay, calcium carbonate, magnesium hydroxide, magnesium carbonate, magnesium oxide, precipitated barium sulfate, hydrotalcite, inorganic fillers such as silica, acrylic resin, benzoguanamine resin. Examples thereof include organic fillers made of fluorocarbon resins such as silicone resins and Teflon, but preferably have cleavability such as talc, kaolin, and clay,
Further, it is preferable that the hardness of the thermal head is relatively low, but the thermal head has cleaning properties. Specifically, in the case of talc, the shot type abrasion degree is preferably 15 to 200 mg. When the abrasion degree is low, head slag is likely to occur, and when it is high, the thermal head protective layer is significantly abraded.

Next, as a method for forming the heat resistant slipping layer, acetone selected from the above materials to suit the coating suitability,
A coating solution is prepared by dissolving or dispersing it in a solvent such as methyl ethyl ketone, toluene, xylene, or water, and the coating solution is applied, dried and solidified by a conventional coating means such as a gravure coater, a roll coater and a wire bar. There is a method of forming a film. The thickness of the coating amounts, i.e. heat-resistant slip layer may have 3.0 mg / m ² or less on a solids basis, preferably with sufficient performance at a thickness of 0.1 to 1.0 mg / m ² A heat resistant slipping layer can be formed. Incidentally, when using a heat-resistant slip layer coating solution containing an isocyanate as a cross-linking agent, since the unreacted isocyanate group often remains in the layer after the application of the coating solution and drying, the reaction In order to complete the above, it is preferable to perform a heat curing treatment after drying.

OHP sheet: a transparent substrate,
What is usually used for sublimation transfer, which is composed of at least a transparent receiving layer, can be used.

Substrate A transparent plastic film is used as the substrate of the OHP sheet. As the plastic film, polyethylene terephthalate film, polyester film such as polyethylene naphthalate film, biaxially oriented polypropylene film, polyamide film, polystyrene film, polyvinylidene chloride film, polyvinyl chloride film, EVOH film, polycarbonate film, fluororesin film , Polymethylmethacrylate film, polybutene-1 film, polyimide film, polyetheretherketone film, polysulfone film, polyethersulfone film, polyetherimide film, polyphenylene sulfide film, polymethylpentene film and the like. Among them, polyethylene terephthalate film, polyethylene naphthalate film, and polyether ether ketone film having high heat resistance are preferable. The surface of these plastic films may be subjected to surface treatment such as easy adhesion treatment, antistatic treatment, corona treatment and the like.

Transparent Receptor Layer The transparent receptive layer is composed of a resin which is easily dyed with a sublimable dye as a main component and, if necessary, various additives such as a release agent. Resins that are easily dyed include polyolefin resins such as polypropylene, halogen resins such as polyvinyl chloride and polyvinylidene chloride, vinyl resins such as polyvinyl acetate and polyacrylate, and copolymers thereof, polyethylene terephthalate. , Polyester resins such as polybutylene terephthalate, polystyrene resins, polyamide resins, copolymers of olefins such as ethylene and propylene with other vinyl monomers, ionomers, cellulose derivatives and the like, and simplex or mixture thereof. . Of these, polyester resins and vinyl resins are preferable. The release agent is for preventing heat fusion with the thermal transfer sheet at the time of image formation, and various kinds of silicone oil such as epoxy modified, amino modified and vinyl modified are used.
Alternatively, these are hardened by addition polymerization etc. with a catalyst,
It exists in the transparent receiving layer or on the surface of the transparent receiving layer. Further, it may be formed as a release layer on the surface of the receiving layer. The transparent receiving layer may be applied by various known coating methods such as gravure coating, gravure reverse coating and roll coating. The thickness of the transparent receiving layer is about 0.5 to 20 μm, preferably about 1 to 10 μm. To do.

When the back layer OHP sheet has a transparent receiving layer on one side,
A back surface layer may be provided on the back surface of the base material on which the transparent receiving layer is not formed in order to improve the transportability of the OHP sheet and prevent curling. As the back surface layer having such a function, a material obtained by adding an organic filler such as a fluororesin or a polyamide resin to an acrylic resin can be used. Further, a back surface layer made of a composition containing an acrylic polyol and an organic filler may be used. Examples of the acrylic polyol include polymers such as ethylene glycol methacrylate and propylene glycol methacrylate. In addition, the ethylene glycol portion may be trimethylene glycol, butanediol, pentanediol, hexanediol, cyclopentanediol, cyclohexanediol, glycerin, or the like. These acrylic polyols not only contribute to curl prevention, but also easily hold additives such as organic fillers and inorganic fillers, and have good adhesiveness to the substrate.

As the back layer, it is more preferable to use a material obtained by curing an acrylic polyol with a curing agent. As the curing agent, conventionally known ones can be used, but isocyanate compounds are preferable. The isocyanate compound reacts with an acrylic polyol to form a urethane bond, which is cured and three-dimensionalized, whereby heat-resistant storage stability and solvent resistance are improved, and further, adhesion to a substrate is improved. The amount of curing agent added is
1 to 2 equivalents are preferable relative to 1 equivalent of the reactive group of the resin.

The back layer may be only the above-mentioned polymer,
It is preferable to add an organic filler. The function of this filler improves the sheet transportability within the printer, and
The sheet's storability is also improved by preventing blocking. Examples of the organic filler include organic resin fine particles such as acrylic resin filler, polyamide filler, and fluorine filler, or polyethylene wax. Of these, polyamide fillers are particularly preferable. The polyamide-based filler has a spherical shape with a molecular weight of 100,000 to 900,000, and an average particle diameter of 0.01 to 10 μm, particularly 0.1 to
5.0 μm is preferred. Polyamide-based fillers have a high melting point, are thermally stable, have good oil resistance and chemical resistance, and are not easily dyed by dyes. The molecular weight is 10 to 90.
In the worst case, it hardly wears out, has self-lubricating properties, has a low coefficient of friction, and does not easily scratch the rubbed material.
Among the polyamide-based fillers, nylon 12 filler is more preferable than nylon 6 or nylon 66 because it has excellent water resistance and does not change its characteristics due to water absorption. The amount of these fillers added is 0.05% by weight based on the resin.
The range of 2 to 2% by weight is preferable. OH if too much is added
The transparency as a P sheet is impaired.

The back surface layer is formed by adding the above-mentioned resins and organic fillers and kneading them sufficiently with a solvent, a diluent, etc. to prepare a coating solution, and then preparing the other surface of the base sheet. Similarly to the means for forming the image receiving layer, it may be applied by, for example, gravure coating, gravure reverse coating, or the like.

[0031]

EXAMPLES The thermal transfer image-receiving sheet of the present invention will be described below with reference to examples. Unless otherwise specified, “part” means “part by weight” and the ratio is based on weight.

Example 1 Preparation of Thermal Transfer Sheet As a base film, a polyethylene terephthalate film (6FK203E: Diafoil Hoechst Co., Ltd.)
Made, with easy adhesion treatment on one side). First, a primer layer having the following composition and a back surface layer are sequentially formed by gravure coating on the non-easy-adhesion treated surface of the substrate. The coating amount is the coating amount when dried.

Primer layer (coating amount: 0.2 g / m ² ) Polyester (VA-ST-1D anchor (modification 3): manufactured by The Inktech Co., Ltd.) 100 parts Dioxane / methyl ethyl ketone (= 2/1) 900 parts Back layer (Coating amount: 0.8 g / m ² ) Polyvinyl butyral (STF-X (1): The Inktech Co., Ltd.) 150 parts Isocyanate curing agent (TDI: Tolylene diisocyanate) (Bernock D-750- 45A: manufactured by Dainippon Ink and Chemicals, Inc. 60 parts Amino curing catalyst (Desmorapid PP: manufactured by The Inktech Co., Ltd.) 0.14 parts Methyl ethyl ketone / toluene (= 1/1) 80 parts

On the other surface of the base material, yellow having the following composition,
The magenta and cyan dye layers were formed surface-sequentially in the longitudinal direction of a long strip-shaped substrate with a length of 210 mm in this order by gravure printing. After coating the dye layer, slitting was performed to a width of 140 mm to prepare a thermal transfer sheet.

Yellow dye layer (coating amount: 0.6 g / m ² ) Yellow dye (Foron.BYS-6GL: manufactured by Sand Co.) 2.25 parts Yellow dye (Macrolex Yellow 6G: manufactured by Bayer Co.) 1.53 parts acetoacetal Resin (KS-5: Sekisui Chemical Co., Ltd.) 3.4 parts Polyethylene powder (MF-8F: Outer Wax Co., Ltd.) 0.24 parts Methyl ethyl ketone / toluene (= 1/1 ) 93 parts Magenta dye layer (coating) Amount 0.6 g / m ² ) Magenta dye (Biscript SRT: manufactured by Bayer) 0.5 part Magenta dye (Oil Red # 5304, SS: manufactured by Arimoto Chemical Co., Ltd.) 4 parts Acetoacetal resin ( KS-5: Sekisui Chemical Co., Ltd. 3.4 parts Polyethylene powder (MF-8F: Outer Wax Co., Ltd.) 0.24 parts Methyl ethyl ketone / toluene (= 1/1) 94 parts Cyan dye layer (coating amount 1 .2 g / ²⁾ cyan dye manufactured by (DH-C2 Nippon Kayaku Co., Ltd.) 5 parts of cyan dye (Foron.B.Blue SR: Sandoz Ltd.) 1.5 parts of acetal resin (KS-5: manufactured by Sekisui Chemical Co., Ltd. 3.2 parts Polyethylene powder (MF-8F: manufactured by Outer Wax Co.) 0.3 parts Methyl ethyl ketone / toluene (= 1/1) 90 parts

Preparation of OHP sheet: As a base film, a polyethylene terephthalate film (Lumirror 7
5T60: manufactured by Toray Industries, Inc., a transparent receiving layer having the following composition is formed on one surface by gravure coating. The coating amount is the coating amount when dried.

Transparent receiving layer (coating amount: 4.5 g / m ² ) Vinyl chloride vinyl acetate copolymer (VA ST-P 1000A: manufactured by The Inktech Co., Ltd.) 90 parts Polyester (VA ST-P V-6 (30) Varnish: The Inktech Co., Ltd. 40 parts Epoxy-modified silicone (X-22-3000E: Shin-Etsu Chemical Co., Ltd.) 0.6 part Amino-modified silicone (X-22-3050C: Shin-Etsu Chemical) Industrial Co., Ltd. 0.6 parts Methyl ethyl ketone / toluene (= 1/1) 40 parts

On the other hand, a polyethylene terephthalate film (Lumirror 38E20: manufactured by Toray Industries, Inc.) is used as a support for the OHP sheet (peeled off at the time of projection), and a primer layer and a back surface layer having the following composition are formed on one side thereof. .

Primer layer (coating amount: 0.2 g / m ² ) Polyester (VA ST-1 D anchor (modified 4): manufactured by The Inktech Co., Ltd.) 100 parts Methyl ethyl ketone / toluene / ethyl acetate (= 1/1) / 1) 300 parts Back surface layer (Coating amount: 0.6 g / m ² ) Acrylic resin (VA ST-P back S: manufactured by The Inktech Co., Ltd.) 5 parts Acrylic resin (ST-P FL slip agent, Teflon filler) Enter: The Inktech Co., Ltd.) 1 part Methyl ethyl ketone 2 parts

Next, a primer layer and an adhesive layer having the following composition are coated and formed on the side of the support on which the back surface layer is not formed, and the coated surface and the transparent receiving layer of the above-mentioned base material coated with the receiving layer are formed. The surface on the side not to be formed is overlapped and attached by dry lamination.

Primer layer (coating amount: 0.2 g / m ² ) Urethane resin (DP urethane: Showa Ink Industry Co., Ltd.) 60 parts Isocyanate compound (Coronate 2030: Nippon Polyurethane Industry Co., Ltd.) 1 part Methyl ethyl ketone / toluene / Ethyl acetate (= 1/1/1) 10 parts Adhesive (application amount 4.0 g / m ² ) Polyacrylic ester emulsion (Esdyne AE386: Sekisui Chemical Co., Ltd.) 10 parts Polyacrylic ester Emulsion (Esdyne AE387: Sekisui Chemical Co., Ltd.) 10 parts Pure water 20 parts

Next, an antistatic agent having the following composition is applied to the front and back of the laminated layer so that the surface electric resistance of the front and back is 1.0 × 10 ¹³ [Ω] or less. Then
The sheet was cut into A5 size and used as an OHP sheet used in the present invention.

Antistatic agent Statiside concentrated solution (quaternary ammonium compound / isopropyl alcohol / ethanol = 59/40/1: manufactured by Takihara Sangyo Co., Ltd.) 1 part Isopropyl alcohol 1200 parts

Image formation: Using the thermal transfer sheet and the OHP sheet prepared above, the following respective image-formed OHP sheets were prepared. Yellow component density (Y
A yellow image with y) of 0.5 was formed. Similarly, a magenta image having a magenta component density (Mm) of 0.5 and a cyan image having a cyan component density (Cc) of 0.5 were formed.

Example 2 An OHP sheet having an image formed thereon was obtained in the same manner as in Example 1 except that a cyan dye layer having the following composition was used.

Cyan dye layer (coating amount 1.1 g / m ² ) Acetoacetal resin (KS-5: Sekisui Chemical Co., Ltd.) 3.2 parts Acetoacetal resin (KS-1: Sekisui Chemical Co., Ltd.) 0.3 parts Dye (TSD-4: Sankyo Chemical Co., Ltd.) 4.6 parts Dye (DO Cyan 715: Orient Co., Ltd.) 0.8 parts Polyethylene powder (MF-8F: Outer Wax Company) Made) 0.4 parts methyl ethyl ketone / toluene (= 1/1) 91 parts

Example 3 An OHP sheet having an image formed thereon was obtained in the same manner as in Example 1 except that a magenta dye layer having the following composition was used.

Magenta dye layer (coating amount 0.9 g / m ² ) Acetoacetal resin (KS-5: manufactured by Sekisui Chemical Co., Ltd.) 3.6 parts Acetoacetal resin (KS-1: Sekisui Chemical Co., Ltd.) 0.3 parts Dye (Miclex R.V.R-SS: Bayer) 1.6 parts Dye (MS Red G: Mitsui Toatsu Co., Ltd.) 2.9 parts Polyethylene powder (MF-8F: Outer wax company) 0.3 parts Methyl ethyl ketone / toluene (= 1/1) 92 parts

Comparative Example Example 1 was repeated except that a dye layer having the following composition was used as the thermal transfer sheet used in the comparative example.
An OHP sheet on which an image was formed was obtained in the same manner as in.

Yellow dye layer (coating amount 0.7 g / m ² ) Acetoacetal resin (KS-5: manufactured by Sekisui Chemical Co., Ltd.) 3.5 parts Polyvinyl butyral resin (BL-3: Sekisui Chemical Co., Ltd.) 0.4 parts Dye (Folon Brilliant Yellow S-6GL pig: Sand) 2.1 parts Dye (MS Red G: Mitsui Toatsu Co., Ltd.) 0.02 parts Polyethylene powder (MF-8F: Outer wax Co., Ltd.) 0.13 parts Methyl ethyl ketone / toluene (= 1/1) 90 parts DMF (dimethylformamide) 3 parts Magenta dye layer (coating amount 0.9 g / m ² ) Acetacetal resin (KS-5: Sekisui Chemical Co., Ltd.) Kogyo Co., Ltd.) 3.6 parts Acetoacetal resin (KS-1: Sekisui Chemical Co., Ltd.) 0.3 parts Dye (Miclex R.V. R-SS: Bayer) 1. Part Dye (MS Red G: manufactured by Mitsui Toatsu Co., Ltd.) 2.9 parts Polyethylene powder (MF-8F: manufactured by Outer Wax Co.) 0.3 part Methyl ethyl ketone / toluene (= 1/1) 92 parts Cyan dye layer ( Coating amount 1.1 g / m ² ) Acetoacetal resin (KS-5: Sekisui Chemical Co., Ltd.) 3.2 parts Acetoacetal resin (KS-1: Sekisui Chemical Co., Ltd.) 0.3 parts Dye (TSD-4: manufactured by Sankyo Chemical Co., Ltd.) 4.6 parts Dye (DO Cyan 715: manufactured by Orient Co., Ltd.) 0.8 part Polyethylene powder (MF-8F: manufactured by Outer Wax Co.) 0.4 part Methyl ethyl ketone / Toluene (= 1/1) 91 parts

Performance Evaluation Image-formed OH produced in Examples and Comparative Examples
Table 1 shows the results of measuring the color density of each color image for each of the P sheets and calculating the turbidity based on the measured values. The color density was measured with a densitometer (RD-918: manufactured by Macbeth Co.). Further, an image was projected by a projector (OHP), and the projected image was visually observed to compare and evaluate the sharpness and the contrast.

[0052]

[Table 1]

[0053]

EFFECT OF THE INVENTION According to the OHP sheet of the present invention, even a projected image obtained by projecting a formed image by a projector (OHP) with transmitted light can obtain a clear and contrasted image. It is easy to recognize the image of the highlight part where the density is low.

Claims (2)

[Claims] 1. An OHP sheet having at least a transparent receiving layer on a transparent substrate, and an image formed by a sublimable dye on the transparent receiving layer, wherein the magenta image has a turbidity of 2 when the concentration of magenta component is 0.5 or less
O formed with an image characterized by 0 to 30%
HP sheet. 2. An OHP sheet having at least a transparent receiving layer on a transparent substrate, and an image formed by a sublimable dye on the transparent receiving layer, wherein the turbidity of a cyan image in the image is When the density of the cyan component is 0.5 or less, 30 ~
OHP formed with an image characterized by being 40%
Sheet.